A Potent Ukrainian Glide-Bomb with very little outlay

[bbofh]

The cheap and nasty answer to Russia's not-so-cheap and very nasty glide-bombs (see the Economist article described below) is even cheaper and even nastier.(see HEAT and HESH rounds on Youtube) Why? Due to being cheap and made/released in great quantities. They'd be great terror-inducing weapons and simply not able to be defended against (not detectable enroute... just like these Russian glide-bombs aren't, once released). The Ukrainian weapon just requires some hydrogen-fueled balloons to get them aloft in any weather conditions.

You mount a GLONASS targeting device on a HEAT munition (High Explosive anti-tank) or HESH (high explosive squash Head) as currently being utilized on UKRAINE's very successful rotary-powered anti-armour drones - but give it set-in-place glider wings with ailerons and an empennage (tail surface) for steerability/stability. You then attach it to one (or two or three - if weight dictates) cheap as chips meteorological radio-sonde balloons and set it to fly UPWARDS - and they can go as high as 32-35kms (115,000 feet altitude ) before bursting and releasing their payload to glide off to a reasonably proximate Russian City in great numbers (and almost simultaneous delivery). With a glide-ratio of 25:1 (8.5 meter wingspan) they could go as far as 130kms at a speed of around 100km/hr. Admittedly it could be an area-designated weapon but could also be delivered with quite some precision. It arrives out of nowhere and is quite undetectable enroute (just like the Russian glide-bombs). Similar to the NAZI V1 Pulse-Jet propelled glide-bombs, but quite a bit cheaper and simpler to produce in large numbers.

Because the means of their delivery would be quite unobvious, the Russkies could not copy-cat the simple technology. The wings could be wooden or aluminium (or a straight-wing plank with a rounded leading edge) and utilize GLONASS- steered model aircraft control tech. The targeting could simply be a homing to pre-set coordinates - with a barometrically triggered vertical dive from a certain height AGL (which achieves fusing of the round as if it had been gun-fired). There would be no need for deceptive routing. A simply go-to point could be programmed in. The burst Meteorological balloon's release mechanism would be a RAM air turbine propeller in the glider's nose unscrewing the balloon attachment once it was in free-flight and achieving a directional gliding velocity. Radiosondes would not be carried. Each radiosonde costs around $200 and weighs around 7 kgs. So around 3 balloons required for an anti-tank round (53.4lbs/24,2kgs) mounted at the glider's Center of gravity would do the job easily (adequate but less rapid buoyancy for the same altitude gain). A 120mm round for an M1 Abrams' tank weighs 40lbs. Actually delivering it over a range of 130 kms would make it a quite potent weapon (particularly if favourable winds aloft could also be factored into the targeting and launch-points). It's all very much in keeping with the philosophy of using a $750 piece of kit to take out a $10M tank. It's become a protracted war of attritive expenses. The Russians have lost many fighters delivering their glide-bombs from ranges of 65 kms or so at heights of over 30Kft. With some design acumen, I think this could be a table-turner. BAE(UK) should get onto it.

from The Economist: | Cheap and nastyRussia’s ferocious glide-bomb campaign ( see economist.com /ukraine-crisis)
For now, Ukraine has no answer to it

[NutLoose]

:ok: you just need to ensure the wind is blowing in the right direction. Welcome to the forums BTW

[bbofh]

The average weather balloon with sufficient lifting force to generate an industry-average two hour time interval to burst-height will ascend at an initial 1000fpm (5m/sec). This climb-rate and 115,000ft burst altitude can be extended by fitting one balloon inside the other and increasing the hydrogen volume (to an extent that can be tolerated by the doubled-up envelope - around double the strength of a single). We speak here of the much cheaper latex balloons used by meteorologists. A single balloon can achieve that average 1000fpm climb-rate with a 4.5kg payload (which normally, in a radio-sonde mode, would include a 1.8kg recovery chute) That climb-rate tapers off exponentially after 70% of height-gain, but the same burst height remains ultimately achievable. If the upper-level winds are generally in the right direction, more ambitious longer-range targets could be reached. Day/night climb-rates differ. Three doubled envelopes (inflated to 1.5 times the usual hydrogen pressure) will achieve the same height with a 35 to 50kg munitions payload. Higher inflation pressures can predicate a burst-height of around 15,000ft higher (i.e. 130,000feet altitude for a doubly-enveloped contraption).

Protection for GPS/GLONASS and radio-control flight surface avionics and the singular lithium-ion battery (against low temperature/pressure of high altitude) can be afforded by encapsulating them within styrofoam shells wrapped in a simple silver-foil survival blanket. Foil blanket would not surround the GPS antenna of course. A shaped light-weight airfoil would greatly increase the glide-range by a factor of two. There would be some scope here for reinforced styrofoam to be the very efficient airfoil surfaces (very surprisingly light-weight and integrally strong). Anybody who has taken delivery of a large object surrounded by internally rib-strengthened styrofoam would no doubt back me up on just how robust (and ultra-light-weight) styrofoam structures can be made. Some of these packagings are almost indestructible. You need to hacksaw them to dispose of that packaging. Styro-foam moulds can be easily constructed and the basic glider mass-produced.

All the very latest weaponry to be seen in prospect on youtube videos are admittedly technological marvels... but are prohibitively expensive - both to develop, deploy, protect, rapidly relocate after use and, in most cases, recover/refuel/re-arm. There is a definite fixation on rotary-powered electric motors being the propulsive mechanism for 99% of cheap battlefield drones. Once the new laser weapons arrive on scene, you can expect the drone fleets to be rapidly decimated by such weapons as the UK's Dragonfire Laser (and its under-development Russian equivalent). Conventional drones will always be needed however - for surveillance and battle-field targeting. The sophisticated expensive non-sacrificial armed drones will also be lost to enemy action much of the time. They are not designed to be lost and the cost of such a loss is an instantly significant effect upon local capability. What is needed for such an attritive war is a mass-produced unsophisticated model aircraft which can be carried aloft from well behind the lines and released to fly undetected (and un-interceptable) to a GPS-nominated medium distance target. It would have a very low radar signature to the point of being almost 100% stealthy. Cheap and mass-produced medium-range weapons such as this Styro-bomb can have both a material and a blitzkrieg psychological effect upon the rear echelons, storage depots and enemy production facilities. So does the ATACMS, but at thousands of times the cost. A Styro-bomb would have the invulnerability afforded by its stealth and silent approach. A THREAT outa Nowhere is a very mind-blowing circumstance to perpetually live with.

Given that Ukraine has an extensive network of agents within Russia, it should also be possible to develop a homer beacon version for precision delivery (even if it needed a built-in offset or an onboard camera for terminal guidance). This would be useful for targeted assassination of individuals located in their domiciles or high value propaganda targets. Modern Stability Augmentation Systems (SAS )are readily adaptable to respond to GPS steering inputs. There are many such SAS and incorporated steerable systems being fitted to light aircraft nowadays. Even a near-miss has a valuable effect upon civilian and production worker morale.

We've seen the highly successful rotary-fan powered steerable remote-controlled drones come into their own on the battlefield over the last few years. Dragonfire and similar systems will soon be decimating them. Even the Predator-style drones will be vulnerable to Dragon-fire interdiction. Many battle-field drones will be being lost to friendly fire. The future of aircraft-carried glide-bombs is "a little up in the air" after around 8 to 10 SU-34 and SU-35 aircraft have been lost to Ukrainian anti-aircraft measures in recent weeks... even though they are high-altitude dropping their FAP glide bomb-loads with fold-out wings from up to 65 kms away from their targets. The advent of F-16's will make that method of delivery even more hazardous. Once you weigh up the cost of mass-production of an ongoing fleet assault of simple balloon-lofted glide-in Styro-bombs, you can see which would be more sustainable for exerting continuing behind-the-front-lines pressure upon enemy troops, production workers and the general populace. Equipping them with Stuka-style paralyzing sirens for their 10 second final diving delivery will have the added effect of paralyzing the Russian war-effort and changing the mindset of the average Russian about the war upon their close neighbour. Styro-bombing is the style of campaign that you could keep up for years ...without breaking the bank and overly relying upon Uncle Sam's Collegiate whimsy and the EU's polka-dotty largesse.

[Chugalug2]

I don't think this is the article in question (it is from last week's Economist) but certainly concerns Ukraine's deep strike drones :-Ukraine’s dronesThe sky’s no limit for Ukraine’s deep-strike programme​​With every step, the air thickens with the smell of petrol. Around a corner is the workshop, and the buzz of manufacturing. Inside, lab-coated technicians are busy assembling grey birds under the glow of overhead lights. Young men in T-shirts scuttle about, before packing the drones in boxes for onward delivery. The destination for some of them will be 1,000km away and more—hunting for important targets inside Russia.

Since President Volodymyr Zelensky prioritised the technology, Ukraine has invested hundreds of millions of dollars into long-range drones, capable of searching out and striking distant targets. Half a dozen firms now make them.

The best of the new models has a range of 3,000km, able to reach Siberia. Born out of necessity—the West has been reluctant to provide Ukraine with long-range weapons—the programme has disrupted much of Russia’s oil and military infrastructure. But the White House is not happy. It is pushing the Ukrainians to stop the strikes.

America’s concerns have varied, from a rise in the oil price to the prospect of an uncontrollable tit-for-tat in which Ukraine could end up the loser. Fears of the latter rose in late March, when Russia inflicted millions of dollars of damage on Ukraine’s energy infrastructure. The attacks revealed gaps in air defences and vulnerabilities to Russia’s new Kh-69 low-altitude cruise missile. On April 11th such missiles destroyed Ukraine’s Trypilska power station, 40km from Kyiv, though it was in range of the capital’s Patriot air-defence systems.

So far, Ukraine is ignoring American advice to call off the strikes. “Detective”, an intelligence officer responsible for part of the programme, says he has not received instructions to dial down operations. Yes, there has been a switch away from aiming at oil infrastructure in the past week, but it is probably temporary. “Our targets change day to day. We keep the Russians on their toes.”

One long-range-drone producer claims that not every American representative agrees with its policy. His contacts “winked” while they delivered warnings. “They’re privately telling us to keep going.” The producer predicted an expansion of Ukraine’s drone programme in the months to come. “Russia is scorching Ukrainian earth. It’s time we did the same to European Russia.”

[bbofh]

Russia’s ferocious glide-bomb campaign
(https://www.economist.com/europe/2024/04/11/russias-ferocious-glide-bomb-campaign)For now, Ukraine has no answer to itFor the past year, Russia has been stepping up its use of glide bombs. In recent months both the size of the bombs and the rate at which they are launched have increased sharply. So far they have mainly been used against Ukrainian troops on the front line. They demonstrated their effectiveness in February by bringing to an end Ukraine’s stubborn defence of Avdiivka, a coking town in the east. But they are now also being used to add a new dimension to Russia’s strategic air campaign, supplementing its limited supply of air-launched cruise missiles.

The glide bombs start life as mostly Soviet-era general-purpose fab bombs, of which there are huge quantities in Russia’s inventory. Last year, the Russians started adding simple, cheap conversion kits to them: wings that pop out when the bomb is released, and a satellite guidance system based on Russia’s GPS equivalent, GLONASS. A slightly more sophisticated and accurate version, which has the wings integrated in the body of the weapon, laser guidance and an anti-jamming antenna, appeared last month. Two of these struck Kharkiv on March 27th.

[bbofh]

"Since President Volodymyr Zelensky prioritised the technology, Ukraine has invested hundreds of millions of dollars into long-range drones, capable of searching out and striking distant targets. Half a dozen firms now make them.

The best of the new models has a range of 3,000km, able to reach Siberia. Born out of necessity—the West has been reluctant to provide Ukraine with long-range weapons—the programme has now disrupted much of Russia’s oil and military infrastructure”

https://www.pprune.org/military-aviation/658854-potent-ukrainian-glide-bomb-very-little-outlay.html

For very little cost overall, such a Balloon-lofted Glider-Borne tank-round munitions project would have a "punch above its weight" effect upon Russian morale. When you talk in terms of quid pro quo, it's not the size of the delivered munition that matters, It's in practical order:

a. the inability to detect and defend against it.

b. Its total unpredictability (no air raid sirens)

c. the minimal resources expended and the fact that valuable delivery systems (aircraft) and propulsion are uninvolved

d. the ability to suddenly and unpredictably upscale the staccato delivery against a particular high-value target

e. the adverse psychological effect upon the Russian populace (the vulnerability syndrome that gets the ego’s attention)

f. When the upper-level winds are favourable, to inexplicably inflict casualties at much greater ranges from the contested border -thereby creating great uncertainty as to exactly who, what and where in Russia is vulnerable.

g. The ability to inflict a second attack some few hours later against the same point target (thereby creating uncertainty amongst the gathering rescue party reaction) aka the well-known “double-tap” that the Russki’s are increasingly using against Ukraine’s major installations.

h. The certainty of taking out high value targets (such as refineries) with a minor munition delivered in threes – but not simultaneously (the staccato Bombard versus the fusillade)

i. Not least, the ability for Ukraine to organically produce such a simplistic weapon in-country via mass production - utilizing available unskilled labour.

j. But if you want to further "seek to simplify", just attach the munition to three latex meteorological balloons when winds aloft are propitiously favourable - and when they burst at 115,000ft, the ordnance will drop somewhere on the Russian side of the lines or in Crimea (straight outa the blue - so to speak)



Ribbed Styrofoam should suffice, but a well smoothed 8.5m elliptical thin plastic airfoil could also be robust and rigid enough for very low speeds (nil flutter). However, unsure what L/D ratio you would achieve via the higher TAS at height - or to what extent it would vary with altitude. Ranges up to 450nms should be reliably achievable. You’d only launch one wave (i.e. the balloon-launched gliders in a swarm) if the upper-level winds guaranteed high-level drift in the right direction. Similarly, a few wing-less impact-fused tank rounds could be used at shorter ranges with a line-of-sight release mechanism similar to what some designs of recoverable drones are using. It’s called harassment and interdiction.

A wing angle of incidence of around 11 degrees sounds about right for those 90km/hr IAS gliding speeds. Think about letting the unswept wing dihedral nail the directional stability and permitting the all-moving fin to do any GPS-guided course correction. Four tail-mounted fins at a mutual 90 degrees (crucifix style) would also achieve something similar if the upper and lower fins were uniformly steerable.

The reason for utilizing cheap latex standard met balloons (3 of) with each of the three being two balloons (double enveloped) inside each other and only the internal one gassed) would be to guarantee a higher burst height. .. of circa 130,000ft... and lowest costs.

However, the stratospheric aerodynamics are headed where no-one's ever went before. Thinking Mach No effects here.

I think that a simple 3.5" diameter propeller that could unwind a screw-thread and free it of the burst balloon drag would suffice once some forward directional speed was achieved (after a single balloon burst). It could then simply freewheel or drop off. But then again, no-one could ever be sure that one balloon would reliably burst followed swiftly by the other two. A more cunning release mechanism may be required. An open/unclasped cup-hook that let all three balloons go once one or two single-point suspension balloons burst - and the craft’s attitude thereupon changed to adopt an attitude for actual sustained forward gliding flight (instead of its lofted vertically-suspended nose-up 90 degree attitude at launch) – might well do the trick. A squadron Launch could be achieved by tethering a dozen balloons together to loosely follow a higher leader carrying the single GPS and steering mechanism.

My understanding is that you would have to stipulate a singular aim-point for the GPS before launch. and utilize a nulling-out steerage mechanism to simply "point at" (i.e. “home on” the GPS target) post release - to keep unit costs down.

But looking at the simplicity of launch and not risking man nor machine nor wasting propellant does very much appeal to my parsimonious nature as far as killing Russkies at the mere cost of a dime a dozen (or better still, taking out a neatly parked row of their aerial war machines). The payload of a 40kg to 50kg impact-fused tank-round seems about right for lofted destructivity and the bonus would always be that if not stealthy, it would still be sneaky... and arrive unannounced - except for its Stuka siren in the last 2500ft plunge towards the target... via a barometric trigger uncovering a port in the nose. The sudden silence of a German buzz-bomb made it into the terror weapon it became.

Overall, the cost of a lengthy war has strained the European and US purse-strings towards an unwillingness to perpetuate the conflict... so a cheaper way of chronically taking the war to the enemy is sorely needed. Without such steps to cheapen the conflict for Ukraine, I can see the pacifiers, pacifists and appeasers forcing Zelensky into negotiating a compromise quasi-permanent “peace-accord” halt not far down track (in around 12 to 18 months). Keep in mind that image of Neville Chamberlain waving his pathetic piece of paper with Hitler’s signature upon it.

For targeting, designation of GPS coordinates is the relatively inexpensive obvious solution. The Russian FAB 500 and FAB 1500 glide bombs may carry more bang but not “more bang for the buck”... and their launch platforms are very vulnerable.

If you ask Dr Google: In what direction does the prevailing upper-level winds blow over Ukraine in Winter?”

He will tell you:

“In northwestern regions the westerlies prevail. Southern regions are the zone of the northerly and northeasterly winds. The average speed increases and ranges from 2 to 4 m/s and in mountainous regions, from 5 to 5 m/s.”

That’s the way the wind blows. It’s altogether in Ukraine’s favour for their winter sports carnival. Barnes Wallis would be proud to be associated with such a device. It would put a bounce back in his step.


Bomber Harris had the right idea when he almost unilaterally decided that carrying the war deep into the enemy heartland was the path to victory. After the Luftwaffe switched from RAF airfields to blitzing London, the German populace were auto-switched to a defensive posture and mindset by nightly RAF raids and the daily USAF bombardment. It might seem like wearing your knuckle-dusters inside your glove as far as destruction goes, but steps in the right direction are always better than just “taking it on the chin”. Even the US Pentagon logistics boys are now delivering the ATACMS with a wink and a nod in the right direction.



It’s worth reflecting upon the fact that the Japanese launched thousands of high altitude balloons carrying incendiary and biological agents in 1944/45 to the USA and that their remnants are still being found all over the US/Canada (see the youtube video). The propaganda effect was squished by a D notice courtesy of the FBI’s J. Edgar Hoover. Hamas has previously done something very similar on a large scale from Gaza with pyrotechnics attached to party balloons (see youtube video).

[WideScreen]

Not wanting to burst a nice idea, though, what about the coffin corner at the 115K ft altitude when having super simple wings, technically only suitable for GA speeds. This might reduce the glide distance considerable, not to speak about the "learning" of stall recovery procedures integrated in the control module of the bolted on wings.....

[bbofh]

https://www.omnicalculator.com/physics/mach-number

has the multiple-entry factor table to determine Mach No:

Mach number calculator

speed of object (IAS) = 90km/hr

speed of sound = 1063.4 km/hr

air temperature (ISA) = -56 degs Celsius

==>> mach .08643 (i.e. doubt any shock-waves would form or that we should see any Prandtl-Meyer effects)

Unswept straight elliptical wings with positive dihedral should not be affected by a lack of yaw-damping. Once naturally assuming non balloon-lofted height circa115Kft to 130Kft (i.e. once freed of the burst balloons), a properly weight-configured aerodynamic vehicle should naturally assume gliding flight at the designed-in speed. Due to the higher TAS initially, the glide ratio should be fairly constant and consistent. The wing-leveller would be courtesy of rudder steering of the GPS steerable top and bottom fins (of the four cruciform tail-fins). They will maintain fore-aft axis alignment with the distant GPS defined target. It's a point-and-shoot arrangement that continually "nulls out" x-wind effect and homes on the target as a destination waypoint. As there'd be no fuel consumption, C of G change or speed variance, the glide should be quite unperturbed by localized air-mass variance effects at that low speed (i.e. upper-level turbulence). It should be quite speed-stable. Entry into a vertical dive upon arrival at the target coords can be at any height (with a barometric trigger for either/both the Hollywood siren's paralyzing noise effects and a GPS dictated hard-over on the horizontal tail surfaces for vertical dive-entry).

Contrasted against the many hundreds of millions being spent on highly sophisticated drones for distant bombardment of enemy HQ's, storage facilities, barracks, refineries and factories, such a simple and uncomplicated weapon would only be subject to the vagaries of wind. Detecting, countering or target area interdicting such a weapon would be tantamount to impossible. It's the quid pro quo that costs but a few quid. One of the advantages of such an apparently aimless, wandering but poignant and pointing (yet accurate) homing weapon is its unpredictability. It can end up approaching from completely unexpected directions (not that it would be noticed at such low speeds). Imagine the forward fuselage being an egg-shaped styrofoam pod (with the nose's cuphook suspension point, 50kg munition, battery, GPS kit and barometric switch) and with the CRUCIFORM fin empennage being mounted aft on 3.5m of 150mm drain-pipe (USD $100). 8.5 metre wings would be ribbed styrofoam.

For easily packaged transport, the wings could be sectioned into 4 pieces and glued via locating lugs to fuselage pod and to the internal ribs of outer wing sections on launch-site. Styrofoam is readily amenable to a simple instant Superglue adhesion (per many youtube videos). Should be good for +4.5/-2.5g inflight loadings.

[WideScreen]

Using this for CAS/TAS conversions:

https://aerotoolbox.com/airspeed-conversions/

And

L = 0.5 * CL * Rho * v^2 * S
Or
S = L / (0.5 * CL * Rho * v^2)
Or
v = SQRT (L/(0.5 * CL * Rho * S))

Bad aerodynamic quality wing, so assume CL=1
At 130K ft altitude, Rho is less than 1% of the sea level (assume 0.5%), so Rho = 0.005 * 1.2 = 0.006 kg/m3

With 90 km/h TAS (let's make it easy and assume 108 km/h = 30 m/s), gives a CAS of 1.7 m/s.

Assume a required lift of 50kg.

Results in S = 50 / (0.5 * 1 * 0.006 * 1.7 * 1.7) = 5767 m2 (yeah ...)

To compare, a Cessna 172 at sea level (weight 1200 kg, assumed stall speed 20 m/s):

S = 1200 / (0.5 * 1.2 * 1.2 * 20 * 20) = 4 m2 wing surface
The actual Cessna wing surface is a little bigger, though the magnitude is correct.

The glide bomb with a more reasonable wing surface of 2 m2, gives a CAS at 130K ft altitude:

v = Sqrt ( 50 / (0.5 * 1 * 0.006 * 2)) = 91 m/s
TAS = 810 m/s

Also ridiculous, supersonic.

And, we have the challenge of getting from CAS = 0 m/s when the balloon bursts to a flyable CAS. Given the high TAS, a huge amount of (potential) energy needs to be converted into kinetic energy (the TAS), before the thing starts flying.

The Orcs launch their Glide bombs from a fighter yet, at high speeds, so, the glide bomb launch is assured to be in a "wings flying" condition.

Please correct me, when I am wrong.

Another item to keep in mind is, that when the aerodynamic speed CAS is low, the TAS is very high at high altitudes, resulting in high inertial loads on the frame structure, when the frame is maneuvering or experiencing turbulence.

[Xhorst]

I think you've just explained why wings don't work at 130,000 feet.

Probably better off using orbital re-entry aerodynamics at that altitude - adjusting body angle for drag without being torn apart or melting, then transitioning to conventional aerodynamic glide at lower altitude.

Like a space shuttle.

Except that you are not starting with a high horizontal speed. You will attain a high vertical speed pretty quickly though - a starting point is the concept that free-fall terminal velocity of a 150mm diameter 50kg sphere at 130,000 feet is about 17,000 km/h.

[bbofh]

Widescreen
Picking up your thread at:
where I am querying the math,

91 mtrs/sec = 177 knots TAS

Your given figure of 810 m/sec (??) = 1574 knots (??)

So, due to the non-linear relationship caused by temperature change:

Mach 1 at 130,000 feet = ?? (becomes the question)

How Does Altitude Affect the Speed of Sound?
The speed of sound decreases with altitude. This is because higher altitudes have lower air pressure and density, leading to a decrease in sound speed. For instance, at 20,000 meters (66Kft) above sea level, the speed of sound drops to around 295 m/s (572 knots TAS) due to the thinner air.

So the Speed of Sound Decreases with Altitude. Why so? In the troposphere, the speed of sound decreases as altitude increases due to lower temperature.
e.g. Mach 1 at 50Kft in an ISA atmosphere is 658 mph or 572 knots

but,
Temperature Stabilization: Around the tropopause (near 36,000 ft to 50,000 ft), the temperature stabilizes, causing the speed of sound to level off before it begins to increase in the stratosphere due to rising temperatures.

However Speed of sound never gets down to 91 mtrs/sec (or 177kts TAS)
e.g. Speed of sound at 120,000 feet = 200 mtrs/sec (450 mph / 390kts) (I asked Chuck Yeager)

So I would readily admit to a glider dropping from a burst balloon at 130,000 ft would be approaching Mach 0.454 perhaps... and it certainly would quickly adjust its attitude and lose a few thousand feet in its acceleration to meet the stern demands of the Lift formula... however I doubt that it would suffer structural failure or break the sound barrier. (rho, rho, rho your boat etc etc). One of the main advantages of styrofoam is that cryogenic temperatures tend to stiffen its resolve (which is perhaps why it is most often found as an insulator in refrigerator applications i.e. the immediate surrounds of very large freezer cabinets).

I saw a sailplane at the Narromine National Gliding Championships that had a mainplane that was weirdly made of internally ribbed styrofoam (in a mould). It felt puny and ridiculously flimsy. Owner kept it stashed in an enclosed trailer so that he could keep the level of mirth down to a dull background roar. Unsurprisingly, I heard that it crashed on its 10th or 20th(?) flight after a few months (but due to the exuberant incompetence of its builder and not due structural failure). I was flying a carbon fibre aircraft at the time and it was about as light as you'd ever expect an airfoil to ever be. My 7 month pregnant wife (callsign: BabyLady) could hold the wingtip of the 15m PIK while my mate held the other wing-tip and I inserted the mainspar fork-stub's pin. Nobody could ever believe how much water I used to dump after a cross-country task, crossing the finish-line at high speed and dot feet... positively gushing. It would still be gushing out voluminously after I'd disembarked. The Gliding Federation made it illegal to electrically pump that much water-ballast (45 gals) into a sailplane after that. Coming from a 17m unflapped fiber-glass beast, it gave me new respect for the strength of light-weight materials. Due to the water-ballast, I inadvertently wound the airspeed off the clock at over 300kph going through the start gate on day two. That's what full-span reflex flaperons and an inflatable canopy seal will do to dull the senses. But then again, it was only my 3rd flight in VH-WVA.

[TURIN]

All this takes me back. 😁
1/2Rho*V^2*S was etched into my brain as an apprentice. Seeing it used in these calculations brings a warm fuzzy feeling, I just wish I'd paid more attention in college. 🙄
As an aside, the Space shuttle had a glide ratio of about 4.5/1 so unless these glide bombs are going to have variable geometry wings I'm not sure how this can work.

[Xhorst]

What you're missing is that your glider isn't just going to do 91 m/s or km/h or kts TAS at 130,000' just because you want it to.

It's going to generate very little lift, very little drag, and fall very fast. There is basically no air there! (less than 0.5% sea level density). At some point it will get low enough where sub-sonic aerodynamics will actually enable it to fly like a glider, if it is still in one piece, which it won't be.

You are going to have to either design a supersonic re-entry vehicle that reverts to a glider, or release it at a much lower altitude.

[TURIN]

Anyone here into Kerbal Space video game.
Modelling one of these shouldn't be too hard.

[WideScreen]

Widescreen
......
91 mtrs/sec = 177 knots TAS

Your given figure of 810 m/sec (??) = 1574 knots (??)
......
The 91 m/s is CAS, use his one:

https://aerotoolbox.com/airspeed-conversions/

To convert to TAS (810 m/s).

Lower than this speed and it'll stall. And at the same time, the object is already far above the speed of sound. It won't fly, effectively just drop to earth, where the wings do have some (only a little bit) to control where it goes, IE the aspect of coffin corner.

Speaking about the space shuttle, I think, any object not designed from pure titanium will just start to glow/burn due to the friction (though, I never tested this).

Or, as Xhorst and TURIN write, your object will be shattered at that altitude/speed.

[RatherBeFlying]

I am reminded of a sci-fi novel where the moon was at war with the earth. The moon weapon was a lump of rock launched against weak lunar gravity to impact at a certain point on the earth.

[bbofh]

There’s no doubt that this is now the new battlefield era of drone-wars, superior camouflage and trenches that afford nil protection from incoming. You only have to look at the expansive coverage of drones on Youtube; their sizes, applications and their many varieties. The Predators and Reapers have been going strong now for two decades. However, the Israelis first used Mastiff Drones and IAI Scout RPV’s during the 1982 Lebanon war to sucker the Syrians into turning on their SA-6 radars (which were then taken out by Israeli F-4’s with AGM-78 and AGM-45 missiles). But with the imminent introduction of the UK’s Dragonfire laser weaponry and the Russki’s truck-mounted Pantsir S1 and S2, all the drone’s bold overhead impunity and prolific numbers will soon be changing. These anti-drone measures are known as CUAs (Counter Unmanned Aerial Systems). Not only will there be lots of Blue on Blue aerial engagements by armed drones and ground-fire, but the cost of employing non-sacrificial drones in forward areas will go exponential due to automated attrition. The Russki’s Pantsir S2 has an optional armament of 12 missiles (suitable for taking out quite distant Reaper-size UAV’s) or the alternate much smaller Mini-missiles (48 of them in a load) for the standard 4 or 5 rotor buzz-bombers. The Pantsir’s larger missiles are 1% the cost of a Patriot round. At last count Russia had deployed over 200 of these platforms, and are prioritizing the project for protection of HV targets and tank convoys. Whether via Laser, acoustic or radar detection, the various anti-drone CUAS weapons and jammers can be used on the front-line or in the rear echelons to protect ammo-dumps, staging areas and HQ’s. Just as submarines have an acoustic signature, so do the drones and it is only that level of technology that will eventually be able to discriminate friend from foe. Cannot foresee battlefield drones being equipped with IFF. Germany’s Rheinmetall Corp has a Combat Drone under development that can loiter, acoustically identify and engage enemy drones whilst at the same time doing armed reconnaissance via video-link from as high as 20,000 feet. One variant will have a strap-on high-rate of fire gun-pod for detected drones and enemy trenches. The GSM phone-links make the average battlefield attack or reconnaissance drone very vulnerable to jamming, although many do have a lost-contact “return to Homeplate” feature built-in – once jammed but NOT if their electronic control link is compromised. Once remote operator control is lost, or they go BVLOS, they are simply junk. But since the Russians have started dropping CS gas cannisters into trenches, the importance of counter-measures has taken on a new urgency. CS gas is nasty stuff. It was used in Vietnam to make base-camps uninhabitable, once sanitized of enemy. You blew it into the soil with C4.

Subsurface drones and their counterforce equivalents are represented by the RN’s first generation REMUS. DARPA is developing a range of military drones for US Army and Marines battlefield and enemy rear-echelon use. However, as we saw with the 99.9% failure rate of the cruise and ballistic missies used against Israel by Iran, these aerial swarms are not all that hard to defend against (or deflect harmlessly) particularly when used en masse across the very limited spectrum of a direct-to-target approach. The bill for achieving that effectivity against the Iranian air attack approached $550M… but the “once off” propaganda value was likely worth it.

Now, however, the Russians’ use of FAB 500lb and 1500lb glide bombs has introduced an entirely new challenge for air defence units. Launched by SU-34 and SU-35 fighters from an average of 65kms from their GPS-designated targets, their fold-out airfoils and bolt-on GPS guidance help these elementary weapons punch well above the weight of their dumb-bomb aircraft-delivered munition equivalent when being simply dropped… and not “launched”. The glide-bombs were devastating for the Ukrainians defending Avdiivka. However reportedly the very effective glide-bomb attacks on Avdiivka also cost almost half a squadron of jets over a few days’ strikes (as they were still within Patriot air defence missile range at launch-point). When the Russians hit the main hotel and civic center of Kharkiv a week or so ago (from launch-point Belgorod) they used the hypersonic ISKANDA and S-300 missiles (10 of). That’s about USD$26M worth of munitions expended on (mainly) two targets of little military value. Because they were fired from a point near Belgorod (about a further 26nms away, across the border), the Patriots had no opportunity to intercept. But firing 10 Patriots would have been equal in expenditure. The Ukrainians had good intel on where those missiles came from so, of their 20 odd suicide drones sent off to Belgorod’s environs in retaliation, 13 were shot down. i.e. They were “expected”… and were thus quite a futile gesture.

The point is that Styro-Glider bombs launched in swarms from an upper wind-suitable ground launch-point would arrive unexpectedly and most all would get through. Why? As said earlier, they are a sneaky weapon. You could use a GSM phone to track and/or even release them from the balloons if you wished. But that would be a unique trigger transmission (not the continuous controllability line-of-sight jammable contact required of a rotor-driven or motorized fixed wing weapon-carrying drone). As has been pointed out, a styro-bomb could not be expected to fly/glide after a singular one (of the three) balloons burst at between 115,000 to 130,000 ft. However, what will happen is that the loss of buoyancy will start the two balloon combo descending back down. So what will that achieve? Firstly extended range (You don’t have to take retribution on the missile launch-point within Russia; better to hit something more militarily valuable and flammable at a greater distance… like a power station, refinery or an armaments factory or fuel dump. Secondly, time (i.e. Response attacks are usually expected within a reasonable time-frame – and the Ukrainians fell for that trap). Thirdly, for one thing, one of the objectives of utilizing a balloon-launched glider is the curved homing approach to its GPS coords (eventually) – and an enemy will always be expecting a reactionary strike to be coming straight-in from a predictable direction. The approach to target will be quite noiseless, radar-invisible, undetected and unpredictable timing-wise (The Bat outa Nowhere tactic). And rather than trying to overwhelm with a swarm, you could simply strike very precisely a number of disparate and dislocated targets. The cost by comparison would be minimal… and the panicky populace quite widespread.

But what about the glider’s actual wing-borne flight? 70% of a met balloon’s climb occurs in the first two hours. The rest is at an ever-dissipating rate of climb (during which time, its drift covers even more ground for a greater range). After one balloon burst (always guaranteed to happen eventually) and a nose-hook-suspended descent into thicker air, you would still have GSM/LTE line-of-sight at 40Kft of 200nms… for a manually triggered balloon release (or even a GPS re-targeting). But you could release the remaining two balloons at any height above that - if you wished. For a maximum-range BVLOS pre-programmed strike, you could wait until the glider descends to a height where the glider naturally (i.e. aerodynamically) adopts a flight attitude and slips off its cup-hook suspension point (hook load-relief then permitting the arty round to reposition – see below)… and it starts “homing”. But if still within LOS, how could you make said glider adopt a flight attitude and commence gliding? Put the 120mm/50kg artillery round in the front one-third of a cylindrical tube and use your phone contact to retract a pawl-catch and allow it to slide back under gravity, forcing a gross C of G change and natural adoption of a flight attitude, thus releasing it from the cup-hook and the remaining balloons. How long the Vodka-guzzlers can keep this war going is anybody’s guess. However, if Ukraine is going to depend on continued sophisticated arms support from the USA and EU they’ve got a shock coming. Best they should start seeking to do what Bomber Harris did to the Nazis and taking their lonesome little war to the Russki back-blocks. It will take people-power to ultimately eliminate Putin and his cronies.

[TURIN]

I am reminded of a sci-fi novel where the moon was at war with the earth. The moon weapon was a lump of rock launched against weak lunar gravity to impact at a certain point on the earth.
A similar technique used in The Expanse, the 'Belters' redirected asteroids towards the moon and Earth. Devastating.

[Fly-by-Wife]

I am reminded of a sci-fi novel where the moon was at war with the earth. The moon weapon was a lump of rock launched against weak lunar gravity to impact at a certain point on the earth.
The Moon is a Harsh Mistress - Robert Heinlein. A good read.